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IX                                          CORYPHODQN-                                     2O9
canine tooth only, and was brought up from a depth of 160 feet
during the making of a well at CamberwelL More abundant
remains have since been found in North America.
This genus had a large head, and in some specimens traces of
the " horn cores," so marked in the related Dvnoceras, are to be
noticed. The skull is broad behind and narrowed in front; the
roofing bones show the cellular spaces so characteristic of the
Elephant. The jtigal bone, however, is not, as it is in the
Elephant, placed in the middle of the somewhat massive zygomatic
arch. As in some other primitive Ungulates (e.g. JPhenacodics)
there are twenty dorso-lumbar vertebrae, of which fifteen bore ribs.
The scapula seems to have possessed a peculiar leaf-like form,
swelling in the middle and ending almost in a point above, It
has a well-marked spine, and the acromion projects much. The
fore- as well as the hind-feet are in a state of transition between
plantigradism and digitigradism. It was at one time held that
the animal was digitigrade as to the fore-feet and plantigrade as to
the hind-feet. Though, as has been pointed out, it is a fact that
the hind-feet are often on a different plane of evolution from the
fore-feet, it seems that this amount of difference does not characterise
any Ungulate, not excepting the genus now under consideration.
The toes are very spreading. The pelvic girdle is of great
strength and broadness. The femur, as in the Perissodactyles,
has a well-developed third trochanter; but whereas in this
particular the hind-limb is Perissodactyle, it is Artiodactyle in
the fact that the tibia and the fibula articulate with the astragalus
and calcaneum. The ridged teeth have given the name to the genus.
A curious feature in the structure of the genus are the
slender spines of the dorsal vertebrae, which contrast with the
enormous ones of some other Ungulates—more curious in this
genus, which is of heavy build, than in the lighter Pantolambda,
The back of the animal is short, and the limbs are very spreading,
so that the gait was doubtless shuffling. The large head, and
short and heavy limbs and limb girdles added probably to its
cumbrous walk or trot. The canines are great tusks, and spread
out on both sides of the mouth.1
The late Professor Cope, in 18 74, described the probable appear-
ance of the Coryphodon in the following words:----" The general
appearance of the  Coryphodons, as  determined by the skeleton
* OsborB, Evil. ^mer. MMS. Wat. Hist. x. 1898* p. 81.
VOI* X                                                                     .                              P